Preparation:1. Heat a large nonstick skillet over medium-high heat. Add beef, onion and garlic, and cook, stirring frequently and breaking up meat with a wooden spoon as it cooks, about 5 to 7 minutes. Stir in crushed tomatoes, tomato sauce, salt, oregano, basil and crushed red pepper flakes; simmer 5 minutes to allow flavors to blend.

2. Meanwhile, in a medium bowl, stir together ricotta cheese and 1 cup of mozzarella cheese.

3. Spoon 1/3 of beef mixture into a 5-quart slow cooker. Break 3 lasagna sheets in half and arrange over beef mixture; top with half of ricotta mixture. Repeat with another layer and finish with remaining 1/3 of beef mixture.

4. Cover slow cooker and cook on low setting for 4 to 6 hours. Remove cover; turn off heat and season to taste, if desired.

5. In a small bowl, combine remaining 1/2 cup of mozzarella cheese and Parmesan cheese; sprinkle over beef mixture. Cover and set aside until cheese melts and lasagna firms up, about 10 minutes. Yields 1/6th of dish per serving.

Notes: To boost your vegetable intake, add a can of zucchini in tomato sauce to the meat mixture. You can also add 2 cups of sliced shiitake mushrooms to the beef mixture.